That's the plan now! I have't tried that yet, it's been very windy here lately so not ideal to try and heat things up, flames being blown out and metal cooling down quickly etc but will attack them as soon as I get a chance. Plenty of other jobs to do though so I've been busy with lots of other parts today.
I think it's just 36 years of never having been changed that's made them so locked in place. Many things have been unnecessarily difficult to remove on this car. These and the crankshaft pulley nut (snap-on air gun running off a big compressor didn't do it, after soaking in penetrant) are all that remain. I'll try heat on the nut, too - perhaps not a chisel though. Hopefully it won't be necessary but as a last-resort measure I'll keep the offer in mind, much appreciated.
1975 Giulia GT1300 Junior, 1981 GTV6, some modern German stuff, and a 1958 Messerschmitt KR201.